Du Wen-Hui, Zhu Wei-Qin, Pan Xiao-Hui, Shen Xu-Yang, Chen Si-Yuan, Chen Ke-le, Mushala Kanjihan, Zhang Hang-Jun, Ding Ying
Key Laboratory of Hangzhou City for Ecosystem Protection and Restoration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China.
Huan Jing Ke Xue. 2017 May 8;38(5):2172-2181. doi: 10.13227/j.hjkx.201610124.
Using vermicompost (CV) as raw material, its biochar (CVC350) was prepared at 350℃ and then their physio-biochemical properties were characterized. Furthermore, adsorption studies were performed in a batch system for removing Pb and Cd ions from solution. The characterization results revealed much higher surface area, smaller pore size, greater aromaticity and nonpolarity of CVC350 as compared to CV. Batch adsorption experiments revealed that both the adsorption of Pb and Cd onto CV or CVC350 fitted Langmuir isotherm model very well, and the maximum adsorption capacity of Pb was in the order of CVC350>CV, but no difference was observed for the adsorption capacity of Cd between CV and CVC350. The desorption studies showed that both CV and CVC350 had much higher adsorption rate for Pb than that for Cd, and the Cd adsorbed could be more easily desorbed from CV and CVC350 compared with that for the Pb adsorbed. Both the dynamic adsorption process of Pb onto CV and CVC350 was a rapid process, however, the adsorption process of Cd onto CV and CVC350 could be separated into the first rapid step and the second slower step. The adsorption capacity of Pb or Cd onto CV and CVC350 was only affected by the much lower initial pH of the solution, besides, the adsorption capacity of Cd onto CV and CVC350 was relatively more influenced by the initial pH compared with that of Pb. Moreover, FTIR analysis showed that the adsorption of Pb and Cdon CV depended on the active sites such as aliphatic alcohol, aliphatic acid,carbonates as well as phosphate while that on CVC350 mainly relied on aromatic alcohol, aromatic acid and carbonates.
以蚯蚓粪（CV）为原料，在350℃下制备其生物炭（CVC350），然后对其物理化学性质进行表征。此外，在间歇系统中进行吸附研究，以从溶液中去除铅和镉离子。表征结果表明，与CV相比，CVC350具有更高的比表面积、更小的孔径、更大的芳香性和非极性。间歇吸附实验表明，铅和镉在CV或CVC350上的吸附都很好地符合朗缪尔等温线模型，铅的最大吸附容量顺序为CVC350>CV，但CV和CVC350对镉的吸附容量没有差异。解吸研究表明，CV和CVC350对铅的吸附率均远高于对镉的吸附率，与吸附的铅相比，吸附的镉更容易从CV和CVC350上解吸。铅在CV和CVC350上的动态吸附过程都是快速过程，然而，镉在CV和CVC350上的吸附过程可分为第一步快速吸附和第二步慢速吸附。铅或镉在CV和CVC350上的吸附容量仅受溶液初始pH值较低的影响，此外，与铅相比，镉在CV和CVC350上的吸附容量受初始pH值的影响相对更大。此外，傅里叶变换红外光谱（FTIR）分析表明，铅和镉在CV上的吸附取决于脂肪醇、脂肪酸、碳酸盐以及磷酸盐等活性位点，而在CVC350上的吸附主要依赖于芳香醇、芳香酸和碳酸盐。
